As a long term vanilla E39 enthusiast, I've started looking into Alpina B10s as a potential replacement for the family 520 workorse. My logic being that the E39 is (IMO!) the best version of the 5 series that is the ideal blend of size, comfort, practicality, luxury and build quality. And the B10s are an even better version yet. Given there's a fair few bits that are common between the normal E39 and the Alpinas and both are prone to same niggles/issues/expenses that come with age (gearbox rebuild, corrosion etc) I'd feel more justified in looking after a B10 than spending on maintaining the vanilla version or running any modern depreciating expensive car.

So..... I've done a search comparing 3.3 and 4.6, and started looking at the classifieds, and fully accept that chances are more money will have to be spent to keep things in top condition on top of the purchase price. For example the 3.3 (#184) in Huddersfield is low mileage and has a good mechanical history, but probably needs a bit of bodywork - but I have no idea what kind of cost that would be, especially if the cost takes it up to the price of a sorted 4.6. Trying both a 3.3 and a 4.6 is also easier said than done given rarity of Switchtronic 3.3s currently and how far away they are (not to mention real world difference in fuel consumption + steering preference).

Are the current asking prices anywhere near transacting prices? Having read through a lot of old posts and adverts, either the market has lifted massively or dealers are taking liberties in their pricing - the Millenium Heroes car looks nice but looks very expensive for a 136k mile car (I think it is 1086 on the register).

Apologies for the rambling post, just trying to get my bearings as to where to start and what budget to set (both purchase and maintenance) in order to not pay over the odds!

Firstly, welcome along, I can't fault your logic on the best 5 Series or derivatives you've shortlisted. Impeccable taste!

Your questions are spot on and well considered. About 2 years ago I had the same sort of questions running around in my head when I decided I wanted a B10.

Here's my thoughts, hope they help you.

1. Think long and hard on what you are prepared to accept and compromise on, and what is absolutely a must for you. The reason for this is simply the scarcity of B10s.
A) The 3.3 and 4.6/4.8s are very different propositions so try and sample what you find and judge for yourself. You may feel happier with one over the other or feel happy with either.
B) The paint colours, trim, equipment levels vary so much on these bespoke/individual cars, what are you prepared to accept? Are there deal breakers, or are you happy with anything within reason?
C) Tourings (v rare), or saloon. Auto or manual?

2. As you rightly point out these cars are at the stage of needing TLC and deep pockets - what are you prepared to invest, within reason of course.

3. Mileage, service history, ownership history. Any limits you want to apply (which in itself will restrict your choices).

On price, many of these cars end up at dealers as Alpinas are so specialised the market for people like us is small. People often say Alpina are wonderful to buy, but terrible to sell. It's just reflective of the small market who actually know and want one over a regular BMW.
I think for the E39 series B10s, they are at a critical point in their lives. The very best cars will have been loved and had money no object approaches to their needs as they age. These cars will of course demand high prices, but if they sell at those prices or not is another matter. These cars are rare these days.
The other cars will invariably have issues, and inevitably it's about assessing how much effort and expense they will need. Of course you need to avoid the money pits, but as you know they all need some investment.
Prices for a 3.3 v 4.6 are remarkably similar. Often this is reflective of a sorted car that's been properly cared for and perhaps had some major bills in its history.

Having read what I've written, I'm not sure I'm helping you much!
I guess in a nutshell you need to decide what are your must haves in a B10, and then find the best example you can that you're happy to invest in.
Be prepared to wait for the right car, having time on your side will help as they are rare cars, especially one that ticks your boxes.

It's a buyers market, so don't be afraid to haggle with dealers! Private sales are preferable as you can gauge if it's been owned by a real lover of the brand, in which case you'll be on safe ground (mostly!).

Good luck in your decision making but my small contribution would be to drive both a straight six and a V8 engined car.

From my experience the supposed steering difference between the cars is almost entirely negated by the beauty of Alpina handling - certainly I can never recall a single B10 V8 or V8S owner ever bemoaning the steering on this forum.

On the other hand there is a gulf of difference in the perfomance stakes. A 3.3 is a quick car as its performance is right up there with a comtemporary 540i but both cars would lose sight of the V8 cars as they were right up to the E39 M5 in terms of performance with just a tenth of a second in the 0-60 times between the M5 and the B10 V8S.

Performance aside the single significant difference between the straight six and V8 Alpina cars is that the straight six car was offered with a manual gearbox; this in itself is sufficient to sway peoples minds over one engine or another but it does come back to the first sentence of my post - drive both cars, in particular use the Switch-Tronic in manual mode and if you don't think you can get used to it, and won't miss the extra performance of the V8 then get a lovely silky smooth straight six and revel in the Alpina suspension suppleness and agility._________________E24man

Thanks everyone, I've already narrowed one requirement - one of the main attractions of the Alpina route (over M) was the Switchtronic box (manual is a no go in this particular instance). I think the biggest fear of going the 4.6 route would be the fuel bills, however, there's more choice of V8 at the moment and they're not much more to buy (especially given the extra spec on some) than the limited choice of 3.3!

I'd be interested to hear average maintenance costs - as an example over the last 13 years, bills for tyres, servicing and repairs for our normal E39 have added up to 12k (including gearbox and TC work) over 100k miles. Going forward I know things like the cooling system will need doing as well as rust prevention/correction work and inevitable bits of random 'refreshing' and replacing. I'm guessing things like cooling system was the same on both Alpina and normal E39s and body work is the same (spoilers and wheels aside) hence looking at making the jump - as Metrics says we are at the tipping point where we shift from a choice of the good, the bad and the ugly to just good and ugly.

As long as the cost of servicing/maintaining/refreshing is less than the depreciation/financing costs of pretty much any new car I think I'd be happy. The fact that most new cars (this side of £50k IMO) probably aren't as nice as a good E39 (nevermind a B10) anyway is a massive bonus.

I often read (and see) about these cars becoming rust buckets (jacking points etc) but I'm guessing rust (and anything else) can always be fixed..... for a price. Problem is rust work costs are akin to the length of a piece of string. At least with the mechanical bits you know you can buy new bits when they need doing or source second hand units for electrical bits that go pop and it would make a difference to how the car drives. It does bug me to account for corrosion (especially when there's no hard and fast 'quote' for work) as you never know how isolated an issue is. Is it best to avoid a car that has cosmetic rust (in fear of a lot more that isn't visible underneath) or is there a ball park figure that can be used?

Anyway those are my thoughts and concerns so far, just need to make some time to go see some cars (especially when they're so far away!), and play the waiting game!

Thought I'd put my twopenneth in since I've had both a 3.3 and a 4.6, and for what its worth, I've also had an e39 M5

My 3.3 was immaculate and a lovely car with a great straight 6 engine, although it did need working to get the best out of it. I normally achieved about 27mpg and occasionally manged low 30's on a run. This had to be offset with it's appetite for expensive oil...

My current B10 is an early (1997) v8 and it's a very different animal - much more drive-able due to the extra torque, and a great top end when the opportunity arises to open her up. I didn't pay a kings ransom for the v8 but than it isn't the minter 3.3 was.

Since I've had the car (25k miles, 14 months), I've spent just under £3000 in servicing and replacing damaged / worn / completely dangerous parts, including swapping the shocks.

In terms of steering, I had expected the v8 to be noticeably different to the 3.3 (the M5 had very 'odd' steering at times, but it did have the servotronic option), but if I'm honest the steering on the v8 is probably nicer all round than my 3.3 was. Fuel wise, I get an overall average of 22.7mpg (I have to log all my receipts for work so that's a pretty accurate figure) but have managed near 30mpg on a gentle run and it hasn't used a drop of oil in my ownership.

My verdict - I'd have the 4.6 over the 3.3 and the M5 - it's a great all rounder - not as fast as the M5 by any means, but I think you can use more of the performance more regularly if that makes sense. It's still an ageing e39 so they all have the same potential problems and if I still had the 3.3 I would have expected to have replaced most of the same parts.

Thanks skyetripper - just out of curiosity why did you move from your immaculate 3.3 - I also know what you mean about oil, is that a 6 cylinder 'quirk' or something that affects these engines with age?

I think those maintenance costs are more than fair considering it would take me a few years to rack up those miles - key would be to have a decent service history and stack of invoices to know where a car stands as a gearbox refurb and a suspension overhaul/brakes would easily rack up a bill in excess of that I'd imagine. That's before any tin worm gets to it......

Having a look at autotrader I can see there's a silver facelift V8 that's been steadily dropping in price over the last month but it's still done 120k miles and it's somewhat irksome that when it was 4.5 years younger with 50k fewer miles on ebay it couldn't get much interest beyond £5k. This might sound silly but a part of me is tempted to take a punt on a cheaper/less than perfect spec car (but ideally not a money pit) just to get a feel for the model/brand and work upwards rather than risk ruining a mint low miles well looked after expensive example.